Speakers and Soundproofing

OK - The first "mod" was to replace the factory speakers. I'm not someone who needs a big boomin' system w/ massive subwoofers, but I also don't like to my music to sound like it's coming out of an old clock radio. I had some Polk speakers in my GTI back in the day that sounded great, so I installed 4 Polk DB652 speakers in all 4 doors. I chose these because they were the only coaxial Polk 6.5 speaker that was available on Crutchfield, and since I have a Venue SE I don't have the separate tweeters up front.

While I was taking off the door panels, I also applied ResoNix CLD to the insides of the doors. To be honest, I always felt that the Venue is a little bit noisy/buzzy while driving it so I started looking into ways to decrease that. ResoNix is a constrained layer damper that prevents vibration of large panels. Most people are familiar with Dynamat, and this is the same concept, same type of product But ResoNix seemed to be the best in terms of performance AND "longevity". By longevity, I mean that some of the cheaper brands of CLD are known to melt in hot temperatures, and the last thing I wanted was to have a gooey mess in my car when summer came around.

Here's one of the door panels.... I may have overdone it, but this is the first time I did anything like this. The doors sound and feel incredibly solid when you open/close them, or just tap them from the outside.

Next up....More sound control. I decided to treat the entire car w/ mass loaded vinyl. MLV is basically just a heavy vinyl sheet (typically 1 lb per square ft) that blocks sound. A lot of people think that CLD will block sound, but it won't. The purpose of CLD is to stop vibrations, but it won't do anything for road or engine noise.

The MLV install was a major undertaking, mainly because you have to apply as much of an unbroken barrier as possible. "Spot treating" with MLV doesn't really work, in the same way that closing a window 90% doesn't really make a big difference at blocking a lawnmower running outside, but closing it 100% makes a big difference. Don't think that you can MLV a car in an afternoon, or even a few days. I worked on it off and on in my spare time (evenings and weekends, mainly) for around a month. Fortunately I work from home and I have access to a 2nd car if necessary. But at one point or another, I had almost every interior part out of the car. That includes the seats, carpet, trim panels, dashboard, etc. 😲

I definitely should have taken a picture of the car torn apart, but I didn't. This is the only MLV photo I have: The passenger footwell carpet+padding lifted up.

The MLV install wasn't the only thing I was doing at this time.. While I had the car apart, I also added ResoNix to the trunk and spare tire well. I also put a bit on the floor where needed, but most of the metal on the floor is pretty rigid and doesn't vibrate. I also took down the headliner, and put ResoNix on the ceiling.

Lessons learned:
As I said before, this was a big job. Looking back, I definitely should not have started by doing the interior firewall. Taking the dashboard and all associated pieces out takes a long time, and in the end I think there are just too many gaps in the MLV to be effective in that area. There I had to work around the holes in the firewall for the brake & clutch pedals, the steering column, the cabin air intake, and the heater core and A/C hoses. My recommendation would be to do the floor and as high up under the dash as you can go without taking it apart.

For what it's worth, I think the things that made the most difference were applying CLD to the ceiling, and the MLV added on the front floor (The engine buzzing from the area behind the shifter and USB port is much more muffled).